Final answer:
Def Leppard's best-selling album is 'Hysteria,' released in 1987, inspired by the media attention on their drummer Rick Allen's recovery and return to the band after an accident.
Step-by-step explanation:
The hard rock band whose best-selling album to date is 1987's Hysteria is Def Leppard. The album was named following the intense media attention that the drummer, Rick Allen, received after a car accident led to the amputation of his left arm.
Despite this tragedy, Allen continued to play with the band using a customized drum kit. Hysteria was a huge commercial success, producing seven hit singles and selling over 20 million copies worldwide, making it one of the best-selling albums of all time.